Blattläuse, commonly known as aphids, are small insects that belong to the family Aphididae. They are typically found on the undersides of leaves and can vary in color, including green, black, and yellow. These pests feed on plant sap, which can weaken plants and lead to stunted growth. In addition to damaging plants, Blattläuse can also produce a sticky substance called honeydew, which attracts other insects like ants. They reproduce quickly, often giving birth to live young, which can lead to large infestations if not controlled. Effective management includes natural predators like ladybugs and the use of insecticidal soaps.